What Are the Different Types of Multiple Sclerosis?
Progressive Relapsing Multiple Sclerosis
Progressive relapsing multiple sclerosis is the least common form. Relapses or attacks happen every so often. But symptoms continue and get worse between relapses.
This type is rare enough that doctors don’t know much about it. Probably around 5% of people with multiple sclerosis have this form. In many ways, it seems similar to primary progressive MS.
What Causes Multiple Sclerosis?
No one knows. Tantalizing clues have sparked research in many areas, but there are no definite answers. Some theories include:
- Geography. People in colder parts of the world get MS more often than those in the warmer parts. Researchers are looking into how vitamin D and sunlight might protect against the disease.
- Smoking. Tobacco may raise the risk slightly. But it's not the whole story.
- Genetics. Genes do play a role. If an identical twin has MS, the other twin has a 20% to 40% chance of getting it. Siblings have a 3% to 5% chance if a brother or sister has it.
- Vaccines. Extensive research has essentially ruled out vaccines as a cause of MS.
- Epstein-Barr virus exposure. Some research has shown that people who develop MS have antibodies to the EBV in their bodies. That means they have been exposed to the virus. It has also shown that the risk of developing MS is much higher in people who have been ill with EBV.
Multiple sclerosis is probably an autoimmune disease. Like lupus or rheumatoid arthritis, the body creates antibodies against itself, causing damage. In MS, the damage occurs in the lining, or myelin, of nerves.